Organopolysiloxane emulsions and their production

ABSTRACT

This invention relates to aqueous emulsions comprising a polyorganosiloxane and a wax, and to methods of production of such emulsions. The emulsions are of the type oil-in-water. An organopolysiloxane is polymerized in admixture with a molten wax, thereby forming a blend of the wax with an organopolysiloxane of increased molecular weight, and the said blend of polymer and molten wax is emulsified in water in the presence of a surfactant. The emulsions are useful in personal care applications such as on hair, skin, mucous membrane or teeth. The emulsions are also useful in applications such as paints, water based coatings, textile fiber treatment, leather lubrication, fabric softening, fabric care in laundry applications, homecare, release agents and oil drag reduction.

RELATED APPLICATIONS

This application claims priority to and all the advantages ofInternational Patent Application No. PCT/EP2010/054220, filed on Mar.30, 2010, which claims priority to Great Britain Patent Application No.GB 0905502.1, filed on Mar. 31, 2009.

This invention relates to aqueous emulsions comprising apolyorganosiloxane and a wax, and to methods of production of suchemulsions. The emulsions are of the type oil-in-water.

Many personal care products such as face, hand and body crèmes,shampoos, sunscreen formulations and colour cosmetics such as mascaraand foundations are emulsions or other dispersions. High molecularweight polyorganosiloxanes are used in many applications in conjunctionwith organic (non-silicon-containing) ingredients, for example for usein personal care, often providing synergistic effects. The organicingredients can be waxes or can be incorporated in organic waxes.However polyorganosiloxanes are not compatible (miscible) with manyorganic ingredients causing problems in obtaining stable dispersions.

WO-A-2006/106362 describes preparing a diluted organopolysiloxanecontaining polymer by the polycondensation of siloxane containingmonomers and/or oligomers which comprise condensable groups in thepresence of an organopolysiloxane and/or an organic based diluentmaterial, a suitable catalyst and optionally an end-blocking agent; andwhere required quenching the polymerisation process. The diluentmaterial is substantially retained within the resulting dilutedorganopolysiloxane. The diluent needs to be compatible with theorganopolysiloxane since otherwise it will exude out of the compositionwith time. WO-A-2008/045427 describes a method of making a siliconeoil-in-water emulsion comprising the further steps of introducing one ormore surfactants into the diluted organopolysiloxane to form ahomogenous oil phase, adding 0.1-10 percent by weight water to thehomogenous oil phase to form a water-in-oil emulsion, applying shear tothe water-in-oil emulsion to cause inversion of the water-in-oilemulsion to an oil-in-water emulsion; and optionally diluting theoil-in-water emulsion by adding more water.

U.S. Pat. No. 5,262,087 describes a water-in-oil emulsified compositionwhich comprises a wax composition formed by radical polymerisation ofpolysiloxanes and wax. Such radical polymerisation will lead to randomgrafting and crosslinking. JP 2000-026726 describes an emulsion obtainedby polymerizing a specified organic silicon compound in the presence ofa solvent in an ionic surfactant system. U.S. Pat. No. 5,914,362describes an emulsion prepared from the reaction of (A) a primarysilicone composition and (B) a polydiorganosiloxane having condensableterminal groups in a non polar organic medium selected frompolyisobutylene and mineral oil. EP0802231 describes a siliconecomposition prepared by reacting a mixture comprising (i) mineral oil,(ii) a polyorganosiloxane, (iii) a silicon compound and (iv) a catalyticamount of a catalyst. U.S. Pat. No. 4,990,556 describes a cured siliconerubber containing entrapped mineral oil. Compositions containingorganopolysiloxanes and waxes are described in U.S. Pat. No. 4,404,035and U.S. Pat. No. 5,503,755.

In a method according to the present invention for producing an aqueousemulsion of a polyorganosiloxane and a wax, an organopolysiloxane ispolymerized in admixture with a molten wax, thereby forming a blend ofthe wax with an organopolysiloxane of increased molecular weight, andthe said blend of polymer and molten wax is emulsified in water in thepresence of a surfactant.

In one preferred procedure the blend of the wax with anorganopolysiloxane of increased molecular weight produced in thepolymerization reaction is emulsified before the reaction product hascooled to a paste or solid. Alternatively the blend of the wax with anorganopolysiloxane of increased molecular weight produced in thepolymerization reaction is cooled to a paste or solid and issubsequently heated to melt the wax and emulsified at a temperatureabove the melting point of the wax.

The blend of wax with organopolysiloxane of increased molecular weightproduced in the polymerization reaction is a very intimate dispersion ofwax in organopolysiloxane or vice versa. It is of course preferred thatthis blend is emulsified before any macroscopic phase separation hasoccurred.

A silicone oil-in-water emulsion according to the invention ischaracterized in that the disperse phase is a blend of a wax with anorganopolysiloxane which has been formed by polymerization in thepresence of the wax.

We have found that by emulsifying the blend of wax with high molecularweight organopolysiloxane formed by polymerization in admixture with thewax, stable emulsions of high molecular weight polyorganosiloxanes inconjunction with organic ingredients can more readily be formed.

The organopolysiloxane starting material is preferably anorganopolysiloxane containing at least one hydroxyl or hydrolysablegroup bonded to silicon and is preferably polymerized by a processcomprising siloxane condensation. The organopolysiloxane startingmaterial can for example be a substantially linear organopolysiloxanecontaining on average more than one hydroxyl or hydrolysable groupbonded to silicon, preferably terminal hydroxyl or hydrolysable groups.The organopolysiloxane can for example have the general formulaX¹-A′-X²  (1)where X¹ and X² are independently selected from silicon containinggroups which contain hydroxyl or hydrolysable substituents and A′represents a polymer chain. Examples of X¹ or X² groups incorporatinghydroxyl and/or hydrolysable substituents include groups terminating asdescribed below:

—Si(OH)₃, —(R^(a))Si(OH)₂, —(R^(a))₂SiOH, —R^(a)Si(OR^(b))₂,—Si(OR^(b))₃, —R^(a) ₂SiOR^(b) or —Ra₂Si—R^(c)—SiR^(d)_(p)(OR^(b))_(3-p) where each R^(a) independently represents amonovalent hydrocarbyl group, for example, an alkyl group, in particularhaving from 1 to 8 carbon atoms, (and is preferably methyl); each R^(b)and R^(d) group is independently an alkyl or alkoxy group in which thealkyl groups suitably have up to 6 carbon atoms; R^(c) is a divalenthydrocarbon group which may be interrupted by one or more siloxanespacers having up to six silicon atoms; and p has the value 0, 1 or 2.Endblocking groups are of the formula —(R^(a))₂SiOH may be particularlypreferred. The linear organopolysiloxane can include a small amount, forexample less than 20%, of unreactive endblocking groups of the formulaR^(a) ₃SiO_(1/2).

The polymer chain A′ is preferably a polydiorganosiloxane chaincomprising siloxane units of formula (2)—(R² ₂SiO)—  (2)in which each R² is independently an organic group such as a hydrocarbongroup having from 1 to 18 carbon atoms, a substituted hydrocarbon grouphaving from 1 to 18 carbon atoms or a hydrocarbonoxy group having up to18 carbon atoms.

Examples of hydrocarbon groups R² include methyl, ethyl, propyl, butyl,vinyl, cyclohexyl, phenyl and tolyl groups. Substituted hydrocarbongroups have one or more hydrogen atoms in a hydrocarbon group replacedwith another substituent, for example a halogen atom such as chlorine,fluorine, bromine or iodine, an oxygen atom containing group such asacrylic, methacrylic, alkoxy or carboxyl, a nitrogen atom containinggroup such as an amino, amido or cyano group, or a sulphur atomcontaining group such as a mercapto group. Examples of substitutedhydrocarbon groups include a propyl group substituted with chlorine orfluorine such as 3,3,3-trifluoropropyl, chlorophenyl,beta-(perfluorobutyl)ethyl or chlorocyclohexyl group. Preferably, atleast some and more preferably substantially all of the groups R² aremethyl. Preferably the polydiorganosiloxanes are polydialkylsiloxanes,most preferably polydimethylsiloxanes.

Polydiorganosiloxanes comprising units of the formula (2) may behomopolymers or copolymers. Mixtures of different polydiorganosiloxanesare also suitable. In the case of polydiorganosiloxane co-polymers thepolymeric chain may comprise a combination of blocks made from chains ofunits depicted in FIG. 2 above where the two R² groups are:

-   -   both alkyl groups (preferably both methyl or ethyl), or    -   alkyl and phenyl groups, or    -   alkyl and fluoropropyl, or    -   alkyl and vinyl or    -   alkyl and hydrogen groups.        Typically at least one block will comprise siloxane units in        which both R² groups are alkyl groups.

The substantially linear organopolysiloxane starting material containingat least one hydroxyl or hydrolysable group bonded to silicon generallyhas a degree of polymerization such that its viscosity is between 5mPa·s and 5000 mPa·s., preferably between 10 mPa·s and 500 mPa·s.Preferably the substantially linear organopolysiloxane is apolydimethylsiloxane having terminal hydroxyl groups bonded to siliconand having a viscosity between 10 mPa·s and 500 mPa·s.

The polymer (A′) used as substantially linear polyorganosiloxanestarting material may alternatively have a block copolymeric backbonecomprising at least one block of siloxane groups of the type depicted informula (2) above and at least one block comprising any suitable organicpolymer chain. Examples of suitable organic polymer chains arepolyacrylic, polyisobutylene and polyether chains.

According to one aspect of the invention such a substantially linearorganopolysiloxane containing at least one hydroxyl or hydrolysablegroup bonded to silicon is polymerized by catalysed condensation of thehydroxyl or hydrolysable groups to form siloxane bonds. Thesubstantially linear organopolysiloxane can for example be substantiallythe only organopolysiloxane starting material used.

Alternatively the organopolysiloxane starting material can be a cyclicorganopolysiloxane, which can be polymerized by a catalysed process ofring opening of the cyclic organopolysiloxane to form siloxane bonds.The cyclic organopolysiloxane used in such a process can for example beoctamethylcyclotetrasiloxane or decamethylcyclopentasiloxane.

The cyclic organopolysiloxane can be the only siloxane material in thepolymerization reaction or can be used together with an organosiliconmaterial which will react with the ring opened cyclicorganopolysiloxane, for example a silane or siloxane material containingat least one hydroxyl or hydrolysable group bonded to silicon. Thissilane or siloxane material can be for example an organopolysiloxanesuch as a substantially linear organopolysiloxane containing at leastone hydroxyl or hydrolysable group bonded to silicon. If such asubstantially linear organopolysiloxane containing at least one hydroxylor hydrolysable group bonded to silicon and a cyclic organopolysiloxaneare polymerized together, they can for example be present in a weightratio of 10:1 to 1:5 in the polymerization reaction mixture.Polymerisation proceeds by a catalysed process of ring opening of thecyclic organopolysiloxane and condensation of the ring opened productwith the substantially linear organopolysiloxane or other silane orsiloxane material containing at least one hydroxyl or hydrolysable groupbonded to silicon.

According to another aspect of the invention, the organopolysiloxanestarting material is a mixture of a substantially linearorganopolysiloxane containing at least one hydroxyl or hydrolysablegroup bonded to silicon and an alkoxysilane having an average of morethan two Si-bonded alkoxy groups per molecule. Such a mixture can bepolymerized by catalysed siloxane condensation of the substantiallylinear organopolysiloxane with the alkoxysilane to form a branchedorganopolysiloxane structure.

The alkoxysilane which is reacted with the linear organopolysiloxanegenerally contains an average of more than 2 silicon-bonded alkoxygroups per molecule. The alkoxy groups preferably each have 1 to 4carbon atoms and most preferably are methyl or ethyl groups. Thealkoxysilane can for example comprise a trialkoxysilane of the formulaR′Si(OR)₃, where R represents an alkyl group having 1 to 4 carbon atomsand R′ represents a monovalent hydrocarbon or substituted hydrocarbongroup having 1 to 18 carbon atoms. Examples of such groups R′ includealkyl groups, for example methyl, ethyl, propyl, butyl, hexyl, octyl,2-ethylhexyl, lauryl or stearyl; cycloalkyl groups, for examplecyclopentyl or cyclohexyl); alkenyl groups, for example vinyl, allyl orhexenyl; aryl groups, for example phenyl or tolyl; aralkyl groups, forexample 2-phenylethyl; and groups obtained by replacing all or part ofthe hydrogen in the preceding organic groups with halogen, for example3,3,3-trifluoropropyl. Examples of preferred trialkoxysilanes includemethyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane,n-octyltriethoxysilane, n-octyltrimethoxysilane, ethyltrimethoxysilane,ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane,phenyltrimethoxysilane and 3,3,3-trifluoropropyltrimethoxysilane.Trialkoxysilanes having a long chain alkyl group R′ having for example 6to 18 carbon atoms, for example n-octyltrimethoxysilane, react with thelinear organopolysiloxane to form a branched organopolysiloxane having along chain alkyl group, for example an octyl group, at the branchingpoint. The presence of such a long chain alkyl group increases thecompatibility of the branched organopolysiloxane with organic materials,for example hydrocarbon solvents or organic polymers.

The alkoxysilane can alternatively be a tetraalkoxysilane such astetraethoxysilane (tetraethyl orthosilicate). Reaction of the linearorganoplysiloxane with a tetraalkoxysilane can form a branchedorganopolysiloxane having Si-alkoxy functionality in the polysiloxanechain as well as branching.

The alkoxysilane can be a partially condensed alkoxysilane in which somealkoxy groups have been hydrolysed and condensed to form siloxanelinkages and some alkoxy groups remain bonded to silicon. Such apartially condensed alkoxysilane preferably contains on average morethan two alkoxy groups per molecule bonded to silicon. The alkoxysilanecan for example be an oligomeric partially condensed trialkoxysilane.Such an oligomer may have a branched structure as well as Si-alkoxygroups to provide further branching sites. Tetraalkoxysilanes can alsobe used in partially condensed form; for example partially condensedtetraethoxysilane containing SiO₂ branching units is widely available.

The alkoxysilane and the substantially linear organopolysiloxanecontaining at least one hydroxyl or hydrolysable group bonded to siliconare preferably reacted in amounts such that the molar ratio of Si-bondedalkoxy groups in the alkoxysilane to hydroxyl or hydrolysable groups inthe substantially linear organopolysiloxane is from 1:100 to 1:1, morepreferably 1:40 to 1:2.

The catalyst for the polymerization of the organopolysiloxane ispreferably a phosphazene catalyst. Phosphazene catalysts are effectivecatalysts both for siloxane condensation and for ring openingpolymerization of cyclic organopolysiloxanes. The phosphazene catalystgenerally contains at least one —(N═P<)— unit and is usually an oligomerhaving up to 10 such phosphazene units, for example having an average offrom 1.5 up to 5 phosphazene units. The phosphazene catalyst can forexample be a halophosphazene, particularly a chlorophosphazene(phosphonitrile chloride), an oxygen-containing halophosphazene, aphosphazene base or an ionic derivative of a phosphazene such as aphosphazenium salt, particularly an ionic derivative of a phosphonitrilehalide such as a perchlorooligophosphazenium salt.

One particularly suitable type of phosphazene catalyst is anoxygen-containing halophosphazene, particularly an oxygen-containingchlorophosphazene. Such an oxygen-containing chlorophosphazene can forexample have the formula Cl(PCl₂═N)_(n)—P(O)Cl or HO(PCl₂═N)_(n)—P(O)Cl₂The average value of n can for example be in the range 1 to 10,particularly 1 to 5. The catalyst may also comprise tautomers of thecatalyst of the formula HO(PCl₂═N)_(n)—P(O)Cl₂ Another type of suitableoxygen-containing chlorophosphazene has the formulaZ′O(PCl₂═N)_(n)—P(O)Cl₂ in which Z′ represents an organosilicon radicalbonded to phosphorus via oxygen, for example a phosphazene catalyst ofthe formula R″₃SiO(PCl₂═N)_(n)—P(O)Cl₂ where each R″ represents amonovalent hydrocarbon or substituted hydrocarbon group having 1 to 18carbon atoms. The catalyst may also comprise condensation products ofsuch an organosilicon-containing phosphazene. All or some of thechlorine atoms in any of the above oxygen-containing phosphazenes can bereplaced by radicals Q, in which Q represents the hydroxyl group,monovalent organic radicals, such as alkoxy radicals or aryloxyradicals, halogen atoms other than chlorine, organosilicon radicals andphosphorus-containing radicals, although this is not preferred.

Another suitable type of phosphazene catalyst is aperchlorooligophosphazenium salt of the formula[Cl₃P—(N═PCl₂)_(n)Cl]⁺Z⁻where n has an average value in the range 1 to 10 and Z represents ananion. The anion is preferably a complex anion and can for example be ofthe formula MX_(v+1) in which M is an element having anelectronegativity on Pauling's scale of from 1.0 to 2.0 and valency vand X is a halogen atom. The element M can for example be phosphorus orantimony. The anion Z can alternatively be a complex anion of theformula [MX_(v−y+1) R³ _(y)]— wherein R³ is an alkyl group having 1 to12 carbon atoms and y has a value between 0 and v, as described in U.S.Pat. No. 5,457,220.

The phosphazene catalyst can alternatively be a phosphazene base,particularly an aminated phosphazene as described in U.S. Pat. No.6,001,928, U.S. Pat. No. 6,054,548 or U.S. Pat. No. 6,448,196. Such aphosphazene base can be formed by reaction of aperchlorooligophosphazenium salt with a secondary amine followed by ionexchange reaction with a basic nucleophile. The secondary amine is forexample of the formula HNR⁴ ₂, and some or all of the chlorophosphazeneoligomer are replaced by —NR⁴ ₂ groups.

The phosphazene catalyst is typically present at 1 or 2 up to 200 partsper million based on the weight of organopolysiloxane startingmaterials, for example at 5 to 50 parts per million. Phosphazenecatalysts have the advantage that the content of undesired low molecularweight cyclic silicones in the polymerisation product is low.

Alternative catalysts which can be used for the organopolysiloxanepolymerization include any of those known to catalyse siloxanecondensation, such as protic acids, Lewis acids, organic and inorganicbases, metal salts and organometallic complexes. Condensation specificcatalysts are preferred. These include acidic condensation catalysts ofthe formula R²⁰SO₃H in which R²⁰ represents an alkyl group preferablyhaving from 6 to 18 carbon atoms such as for example a hexyl or dodecylgroup, an aryl group such as a phenyl group or an alkaryl group such asdinonyl- or didoecyl-naphthyl, for example the catalyst can bedodecylbenzenesulphonic acid. Other condensation specific catalystsinclude n-hexylamine, tetramethylguanidine, carboxylates of rubidium orcaesium, and hydroxides of magnesium, calcium or strontium.

Further alternative catalysts include condensation catalystsincorporating tin, lead, antimony, iron, cadmium, barium, manganese,zinc, chromium, cobalt, nickel, aluminum, gallium or germanium andzirconium. Examples include metal triflates, organic tin metal catalystssuch as triethyltin tartrate, tin octoate, tin oleate, tin naphthate,butyltintri-2-ethylhexoate, tinbutyrate, carbomethoxyphenyl tintrisuberate, isobutyltintriceroate, and diorganotin salts especiallydiorganotin dicarboxylate compounds such as dibutyltin dilaurate,dimethyltin dibutyrate, dibutyltin dimethoxide, dibutyltin diacetate, ordimethyltin bisneodecanoate.

A titanate or zirconate based catalyst can be used, for example acompound according to the general formula Ti[OR²²]₄ where each R²² maybe the same or different and represents a monovalent, primary, secondaryor tertiary aliphatic hydrocarbon group which may be linear or branchedcontaining from 1 to 10 carbon atoms. The titanate may be chelated, forexample with an alkyl acetylacetonate such as methyl or ethylacetylacetonate.

A further alternative catalyst which might be used as the catalyst inthe present invention is any suitable compound providing a source ofanions comprising at least one quadri-substituted boron atom and protonscapable of interaction with at least one silanol group as defined in WO01/79330, for example tetrakis (pentafluoro phenyl) borate anion.

Alternatively polymerization of the organopolysiloxane may be by ahydrosilylation reaction between an unsaturated organic group, forexample an alkenyl or alkynyl group, and an Si—H group in the presenceof a suitable catalyst. In this route suitable silanes may be utilisedas well as siloxane containing monomers and/or oligomers. Thus theorganopolysiloxane can comprise an organopolysiloxane containing alkenylor alkynyl groups which is polymerized with a silane or siloxanematerial having Si—H groups by a hydrosilylation reaction, or anorganopolysiloxane having Si—H groups which is polymerized with anorganic compound containing at least two alkenyl or alkynyl groups by ahydrosilylation reaction. The hydrosilylation reaction is generallyeffected in the presence of a platinum group catalyst.

The organopolysiloxane containing alkenyl or alkynyl groups can belinear or branched, and generally comprises Si-bonded organic groupswhich are hydrocarbon or substituted hydrocarbon groups containing 1 to18 carbon atoms, at least two of which are alkenyl or alkynyl groups.The organopolysiloxane may for example contain the alkenyl or alkynylgroups as terminal groups. Each alkenyl or alkenyl group preferably hasa terminal double bond. Examples of preferred alkenyl groups areH2C═CH—, H₂C═CHCH₂—, H₂C═C(CH₃)CH₂—, H₂C═CHCH₂CH₂—, H₂C═CHCH₂CH₂CH₂—,and H₂C═CHCH₂CH₂CH₂CH₂—. Examples of alkynyl groups include HC≡C— andHC≡CCH₂—. The other organic groups of the organopolysiloxane can forexample be selected from alkyl groups such as methyl, ethyl, propyl,butyl, pentyl, hexyl, heptyl, octyl, undecyl, and octadecyl; cycloalkylsuch as cyclohexyl; aryl such as phenyl, tolyl, xylyl, benzyl, and2-phenylethyl; and halogenated hydrocarbon groups such as3,3,3-trifiuoropropyl, 3-chloropropyl, and dichlorophenyl. Methyl groupsare often preferred. The organopolysiloxane can for example be analkeyl-terminated linear or branched polydimethylsiloxane.

The organopolysiloxane having Si—H groups can be linear or branched. Theother organic groups of the organopolysiloxane can for example beselected from alkyl groups such as methyl, ethyl, propyl, butyl, pentyl,hexyl, heptyl, octyl, undecyl, and octadecyl; cycloalkyl such ascyclohexyl; aryl such as phenyl, tolyl, xylyl, benzyl, and2-phenylethyl; and halogenated hydrocarbon groups such as3,3,3-trifiuoropropyl, 3-chloropropyl, and dichlorophenyl. Methyl groupsare often preferred. The Si—H groups can be terminal, for example theorganopolysiloxane can have dimethylsilyl terminal groups, and/or theSi—H groups can be along the polymer chain, for example theorganopolysiloxane can comprise methylhydrogensiloxane units. Theorganopolysiloxane having Si—H groups can for example be apoly(methylhydrogen)siloxane or a dimethylsiloxanemethylhydrogensiloxane copolymer.

If polymerization by hydrosilylation is used, an organopolysiloxanecontaining alkenyl or alkynyl groups as described above is preferablyreacted with an organopolysiloxane having Si—H groups as describedabove.

The organopolysiloxane containing alkenyl or alkynyl groups canalternatively or additionally be polymerized with a silane containing atleast one Si—H group. Examples of such silanes include halosilanes suchas trichlorosilane, methyldichlorosilane, dimethylchlorosilane, andphenyldichlorosilane, and alkoxysilanes such as trimethoxy silane,triethoxy silane, methyl diethoxy silane, methyl dimethoxy silane andphenyldimethoxy silane.

The organopolysiloxane containing Si—H groups can alternatively oradditionally be polymerized with an organic compound containing at leasttwo alkenyl or alkynyl groups. The alkenyl or alkynyl groups should notbe conjugated and are preferably terminal groups. Suitable organiccompounds include for example 1,5-hexadiene and 1,7-octadiene.

The catalyst for the hydrosilylation reaction is generally a platinumgroup catalyst, that is a metal selected from platinum, rhodium,palladium, osmium, iridium, or ruthenium or a compound of one of thosemetals. Examples of catalysts comprising platinum include chloroplatinicacid, alcohol modified chloroplatinic acids, olefin complexes ofchloroplatinic acid, complexes of chloroplatinic acid anddivinyltetramethyldisiloxane, fine platinum particles adsorbed on carboncarriers, platinum supported on metal oxide carriers such as Pt(Al₂O₃),platinum black, platinum acetylacetonate, platinous halides exemplifiedby PtCl₂, PtCl₄, Pt(CN)₂, and complexes of platinous halides withunsaturated compounds exemplified by ethylene, propylene, andorganovinylsiloxanes. One preferred platinum catalyst is Karstedt'scatalyst, which is a platinum divinyl tetramethyl disiloxane complextypically containing one weight percent of platinum in a solvent such astoluene. Another preferred platinum catalyst is a reaction product ofchloroplatinic acid and an organosilicon compound containing terminalaliphatic unsaturation as described in U.S. Pat. No. 3,419,593. Afurther preferred catalyst is a neutralized complex of platinouschloride and divinyl tetramethyl disiloxane, as described in U.S. Pat.No. 5,175,325.

Examples of hydrosilylation catalyst comprising ruthenium includeRhCl₃(Bu₂S)₃ and ruthenium carbonyl compounds such as ruthenium1,1,1-trifluoroacetylacetonate, ruthenium acetylacetonate andtriruthinium dodecacarbonyl or a ruthenium 1,3-ketoenolate. Examples ofrhodium catalysts include [Rh(O₂CCH₃)₂]₂. Rh(O₂CCH3)₃, Rh₂(C₈H₁₅O₂)₄,Rh(C₅H₇O₂)₃, Rh(C₅H₇O₂)(CO)₂, and Rh(CO)[Ph₃P](C₅H₇O₂). Examples ofiridium catalysts include IrCOOCCH₃)₃ and Ir(C₅H₇O₂)S.

The concentration of the hydrosilylation catalyst in the composition isusually capable of providing the equivalent of at least 1 part permillion of elemental platinum group metal by weight based on theorganopolysiloxane. A catalyst concentration providing the equivalent ofabout 3-50 parts per million of elemental platinum group metal isgenerally the amount preferred.

Typically, the hydrosilylation polymerisation is carried out usingapproximately a 1:1 molar ratio of Si—H groups to alkenyl alkynylgroups. The material containing alkenyl groups may be used in slightexcess to ensure all the Si—H is consumed in the reaction.

The extent of polymerization during the process of the invention ispreferably such that the organopolysiloxane of increased molecularweight produced has a weight average molecular weight Mw at least fivetimes, more preferably at least ten times the weight average molecularweight of the starting organopolysiloxane. The Mw can be measured by gelpermeation chromatography (GPC). The Mw of the organopolysiloxane ofincreased molecular weight produced is preferably at least 50,000, morepreferably at least 100,000, and may be as high as 1,000,000 or more.

By a wax we mean a material which is plastic or malleable attemperatures of 15-20° C., has a melting point of at least 20° C., andhas a low viscosity when melted. Examples for waxes described in theKirk-Othmer encyclopaedia of chemical technology (Article on Waxes byClaude Leray, John Wiley & Sons, Inc. 2006). The wax present during theorganopolysiloxane polymerization generally has a melting point of above20° C. and preferably has a melting point in the range 30 to 100° C.,more preferably 40 to 90° C. The wax can be an organic wax containing nosilicon or can be a silicone wax. For uses in which increasing thecompatibility of the organopolysiloxane formulation with organicmaterials is important, organic waxes are usually preferred althoughsilicone waxes containing long chain organic substituents can alsoincrease compatibility.

The wax can for example be a hydrocarbon wax such as a petroleum-derivedwax, particularly a paraffin wax or microcrystalline wax, aFischer-Tropsch wax, ceresin wax, a polyethylene wax or a mixturethereof. Paraffin waxes contain predominantly straight-chainhydrocarbons with an average chain length of 20 to 30 carbon atoms.Examples of paraffin waxes are sold by IgiWax under the trade markParafflex, such as Parafflex 4750 A granules and Parafflex 4797A.Microcrystalline wax contains a higher percentage of branchedhydrocarbons and naphthenic hydrocarbons. Examples of microcrystallinewaxes are sold by IgiWax under the trade mark Microsere, for exampleMicrosere 5981A. Other organic hydrocarbon waxes that can be used aremontan wax (also known as lignite-wax), ozokerite or slag wax.

The wax can alternatively be a wax comprising carboxylic esters. Manynatural waxes such as beeswax, lanolin, tallow, carnauba and candelilla,as well as tribehenin and waxes derived from plant seeds, fruits, nutsor kernel, such as palm wax, rice bran wax or soy wax, comprise amixture of esters with free acids and/or alcohols. Examples of esterwaxes are palm waxes derived from palm oil sold by IgiWax under thetrade names RD2778A and RD2779A. Some of the softer waxes are referredto as ‘butter’. These types of products are—frequently used in skin careapplications and are for example derived from oilseeds as mango butter,shea butter or cocoa butter. Other examples are illipe, cupuacu,murumuru, sal and kokum butter. Such a butter can be used as all or partof the wax of the invention, provided that the wax has a melting pointof at least 20° C. In general butters can be defined by having a titerpoint of below 40.5° C. but above 20° C. (“Oils of nature” by J.O'Lenick according to AOCS method Tr 1 a-64T).

The wax can alternatively be a long chain fatty acid, a long chain fattyalcohol, a long chain fatty amine, a long chain fatty amide, anethoxylated fatty acid or fatty alcohol, or a long chain alkyl phenol.In general the long chain of the fatty acid, alcohol, amine or amide isan alkyl group of at least 12 and preferably at least 16 carbon atoms,often up to 30 or more carbon atoms.

The wax can alternatively be a polyether wax, for example a solidpolyether polyol or a waxy polyvinyl ether such as that sold by BASFunder the trade mark Lumax V, or a polyetherester.

Examples of silicone waxes are polysiloxanes containing hydrocarbonsubstituents having 12 or more carbon atoms. The polysiloxane ispreferably a polydiorganosiloxane comprising methyl alkyl siloxane units((CH3) (R³) Si02/2), where R³ is a long chain alkyl group having 12 ormore, preferably 16 to 100 carbon atoms, optionally together withdimethyl siloxane units or units of the formula ((CH3) (R⁴) SiO2/2)where R⁴ is an alkyl group having 1-11 carbon atoms, for example ethyl,a cycloalkyl group such as 2-cyclohexylethyl, a haloalkyl group, an arylgroup such as phenyl or an aralkyl group such as 2-phenylpropyl,2-phenylethyl or 2-(t-butylphenylethyl). The methyl group of the abovesiloxane units could be replaced by ethyl or another lower alkyl groupif desired. The long chain alkyl group R³ can optionally be substitutedby polar substituents such as amino, amido, alcohol, alkoxy, or estergroups. Preferably at least 20% of the silicon atoms in the siliconewax, and most preferably at least 50%, have an alkyl substituent having16 to 100 carbon atoms, most preferably 20 to 36 carbon atoms.

Mixtures of different types of waxes can be used, for example a blend ofan ester wax with a hydrocarbon wax.

The wax can be present during the polymerization in any amount from 1 or5% based on the organopolysiloxane up to 150 or 200% based on theorganopolysiloxane. Preferably the weight ratio of organopolysiloxane towax present during the polymerization is from 95:5 to 40:60. The wax canbe melted before contacting the organopolysiloxane, or solid wax can bemixed with the organopolysiloxane and heated to melt the wax whileapplying shear to mix.

The polymerization of the organopolysiloxane is carried out at atemperature above the melting point of the wax. Preferably thetemperature of polymerization is from 5° C. to 30° C. above the meltingpoint of the wax, for example the temperature of polymerization can bein the range 50° C. to 120° C. Most waxes, particularly organic waxessuch as hydrocarbon waxes and ester waxes, are not miscible withorganopolysiloxanes such as a hydroxyl-tipped polydimethylsiloxane. Thewax and the silicones are thus present as a liquid/liquid dispersion andthe polymerisation is therefore a dispersion polymerization.

The polymerization reaction can be terminated when a desired degree ofpolymerization has been reached. This can be determined for example bymonitoring the viscosity of the polymerization reaction mixture or thetorque required to mix it. Polymerisation catalysed by the preferredphosphazene catalysts can be terminated by adding a neutralizing agent,for example a trialkylamine such as trihexylamine in the case of thecatalysts described in U.S. Pat. No. 5,457,220. The time for whichpolymerization is carried out can be varied within wide limits, forexample from 1 or 2 minutes up to 10 hours or more. Polymerisationcatalysed by the preferred phosphazene catalysts is usually carried outfor 2 to 150 minutes.

An inert liquid diluent can be present during the polymerization ifdesired. A diluent can be a silicone based and/or organic based diluentand is generally chosen to have no groups reactive with theorganopolysiloxane. The diluent if used will usually be chosen frommaterials whose presence is desired as an extender or plasticizer in theend product formulation based on the wax silicone blend produced.

Any suitable diluent or combination of diluents may be used in thereaction mixture. In general any of the extenders used inWO-A-2006/106362 can be used. These include each of the following aloneor in combination with others from the list:

-   -   hydrocarbon oils such as mineral oil fractions comprising linear        (e.g. n-paraffinic) mineral oils, branched (iso-paraffinic)        mineral oils, and/or cyclic (referred in some prior art as        naphthenic) mineral oils, the hydrocarbons in the oil fractions        comprising from 5 to 25 carbon atoms per molecule;    -   trialkylsilyl terminated polydialkyl siloxane where the alkyl        groups are preferably methyl groups, where each alkyl group may        be the same or different and comprises from 1 to 6 carbon atoms        but is preferably a methyl group, preferably with a viscosity of        from 100 to 100000 mPa·s at 25° C. and most preferably from 1000        to 60000 mPa·s at 25° C.;    -   polyisobutylenes (PIB);    -   phosphate esters such as trioctyl phosphate;    -   polyalkylbenzenes, linear and/or branched alkylbenzenes such as        heavy alkylates, dodecyl benzene and other alkylarenes;    -   esters of aliphatic monocarboxylic acids;    -   linear or branched mono unsaturated hydrocarbons such as linear        or branched alkenes or mixtures thereof containing from 8 to 25        carbon atoms;    -   natural oils and derivatives thereof.

Preferred diluents include the mineral oil fractions,alkylcycloaliphatic compounds and alkybenzenes includingpolyalkylbenzenes. Any suitable mixture of mineral oil fractions may beused as diluent but high molecular weight extenders, for example havinga molecular weight above 220, are particularly preferred. Examplesinclude alkylcyclohexanes of molecular weight above 220), paraffinichydrocarbons and mixtures thereof containing from 1 to 99%, preferablyfrom 15 to 80% n-paraffinic and/or isoparaffinic hydrocarbons (linearbranched paraffinic) and 1 to 99%, preferably 85 to 20% cyclichydrocarbons (naphthenic) and a maximum of 3%, preferably a maximum of1% aromatic carbon atoms. The cyclic paraffinic hydrocarbons(naphthenics) may contain cyclic and/or polycyclic hydrocarbons.

Alternative preferred diluents suitable for retaining in many productsas an extender or plasticiser comprise non-mineral based natural oils,i.e. oils derived from animals, seeds or nuts and not from petroleum.Such natural oils are generally triglycerides of mixtures of fattyacids, particularly mixtures containing some unsaturated fatty acid.Diluents containing natural oils may for example be preferred for use insome personal care products. The diluent can be a derivative of anatural oil such as a transesterified vegetable oil, a boiled naturaloil, a blown natural oil, or a stand oil (thermally polymerized oil).

The amount of diluent, if used, can for example be up to 60%, usually 5to 40%, of the combined weight of wax, organopolysiloxane and diluent.The diluent may be miscible with either the siloxane, the molten waxphase of both of them. Many diluents are miscible with the wax and willreduce the melting point of the wax, although the amount of diluent ispreferably not so much that the mixture of wax and diluent has a meltingpoint below 20° C.

Any suitable surfactant or combination of surfactants may be used inemulsifying the wax silicone dispersion. The emulsion produced can beeither of the oil-in-water (o/w) or water-in-oil (w/o) type. Thesurfactant can in general be a non-ionic surfactant, a cationicsurfactant, an anionic surfactant, or an amphoteric surfactant. Theamount of surfactant used will vary depending on the surfactant, butgenerally is up to about 30 wt. % based on the polydiorganosiloxane, forexample 0.2 to 20%.

Examples of nonionic surfactants include condensates of ethylene oxidewith long chain fatty alcohols or fatty acids such as a C₄₋₁₆ alcohol,condensates of ethylene oxide with an amine or an amide, condensationproducts of ethylene and propylene oxide, esters of glycerol, sucrose,sorbitol, fatty acid alkylol amides, sucrose esters, fluoro-surfactants,fatty amine oxides, polyoxyalkylene alkyl ethers such as polyethyleneglycol long chain (12-14C) alkyl ether, polyoxyalkylene sorbitan ethers,polyoxyalkylene alkoxylate esters, polyoxyalkylene alkylphenol ethers,ethylene glycol propylene glycol copolymers and alkylpolysaccharides,for example materials of the structure R²⁴O—(R²⁵O)s-(G)_(t) wherein R²⁴represents a linear or branched alkyl group, a linear or branchedalkenyl group or an alkylphenyl group, R²⁵ represents an alkylene group,G represents a reduced sugar, s denotes 0 or a positive integer and trepresent a positive integer as described in U.S. Pat. No. 5,035,832.Alternative nonionic surfactants include polymeric surfactants such aspolyvinyl alcohol (PVA) and polyvinylmethylether. Surfactants containingsilicon atoms can also be used.

Representative examples of suitable commercially available nonionicsurfactants include polyoxyethylene fatty alcohols sold under thetradename BRIJ by Uniqema (ICI Surfactants), Wilmington, Del. Someexamples are BRIJ 35 Liquid, an ethoxylated alcohol known aspolyoxyethylene (23) lauryl ether, and BRIJ 30, another ethoxylatedalcohol known as polyoxyethylene (4) lauryl ether. Similar materials aresold by Croda Europe under the trade marks Volpo L23 and Volpo L4. Someadditional nonionic surfactants include ethoxylated alcohols sold underthe trademark TERGITOL by The Dow Chemical Company, Midland, Mich., suchas TERGITOL TMN-6, an ethoxylated alcohol known as ethoxylatedtrimethylnonanol; and various ethoxylated alcohols, i.e., C12-C14secondary alcohol ethoxylates, sold under the trademarks TERGITOL15-S-5, TERGITOL 15-S-12, TERGITOL 15-S-15, and TERGITOL 15-S-40.

Examples of suitable amphoteric surfactants include imidazolinecompounds, alkylaminoacid salts, and betaines. Specific examples includecocamidopropyl betaine, cocamidopropyl hydroxysulfate, cocobetaine,sodium cocoamidoacetate, cocodimethyl betaine, N-coco-3-aminobutyricacid and imidazolinium carboxyl compounds.

Examples of cationic surfactants include quaternary ammonium hydroxidessuch as octyl trimethyl ammonium hydroxide, dodecyl trimethyl ammoniumhydroxide, hexadecyl trimethyl ammonium hydroxide, octyl dimethyl benzylammonium hydroxide, decyl dimethyl benzyl ammonium hydroxide, didodecyldimethyl ammonium hydroxide, dioctadecyl dimethyl ammonium hydroxide,tallow trimethyl ammonium hydroxide and coco trimethyl ammoniumhydroxide as well as corresponding salts of these materials, fattyamines and fatty acid amides and their derivatives, basic pyridiniumcompounds, quaternary ammonium bases of benzimidazolines andpolypropanolpolyethanol amines. Other representative examples ofsuitable cationic surfactants include alkylamine salts, sulphoniumsalts, and phosphonium salts.

Examples of suitable anionic surfactants include alkyl sulphates such aslauryl sulphate, polymers such as acrylic acid/C₁₀₋₃₀ alkyl acrylatecrosspolymer, alkylbenzenesulfonic acids and salts such ashexylbenzenesulfonic acid, octylbenzenesulfonic acid,decylbenzenesulfonic acid, dodecylbenzenesulfonic acid,cetylbenzenesulfonic acid and myristylbenzenesulfonic acid; the sulphateesters of monoalkyl polyoxyethylene ethers; alkylnapthylsulfonic acid;alkali metal sulforecinates, sulfonated glyceryl esters of fatty acidssuch as sulfonated monoglycerides of coconut oil acids, salts ofsulfonated monovalent alcohol esters, amides of amino sulfonic acids,sulfonated products of fatty acid nitriles, sulfonated aromatichydrocarbons, condensation products of naphthalene sulfonic acids withformaldehyde, sodium octahydroanthracene sulfonate, alkali metal alkylsulphates, ester sulphates, and alkarylsulfonates. Anionic surfactantsinclude alkali metal soaps of higher fatty acids, alkylaryl sulphonatessuch as sodium dodecyl benzene sulphonate, long chain fatty alcoholsulphates, olefin sulphates and olefin sulphonates, sulphatedmonoglycerides, sulphated esters, sulphonated ethoxylated alcohols,sulphosuccinates, alkane sulphonates, phosphate esters, alkylisethionates, alkyl taurates, and alkyl sarcosinates. One example of apreferred anionic surfactant is sold commercially under the nameBio-Soft N-300. It is a triethanolamine linear alkylate sulphonatecomposition marketed by the Stephan Company, Northfield, Ill.

The above surfactants may be used individually or in combination.

The polymerisation catalyst may additionally be the surfactant, or oneof the surfactants, involved in the emulsification process. A family ofcatalysts which can act as surfactants are acidic condensation catalystsof the formula R²⁰SO₃H, for example dodecylbenzenesulphonic acid.

In a preferred procedure the blend of the wax with an organopolysiloxaneof increased molecular weight produced in the polymerization reaction isemulsified by mixing with surfactant and water before the reactionproduct has cooled to a paste or solid. Alternatively the blend of thewax with an organopolysiloxane of increased molecular weight produced inthe polymerization reaction can be cooled below the solidificationtemperature of the wax, for example down to room temperature. Thisyields a paste or solid blend of the wax and the polymerizedorganopolysiloxane depending on the silicone to wax ratio, the hardnessof the wax and the molecular weight of the organosiloxane. The paste orsolid is a very intimate dispersion of wax in organopolysiloxane or viceversa. This paste or solid can be reheated to a temperature above themelting point of the wax in the dispersion, and emulsified by mixingwith surfactant and water.

In one preferred emulsification procedure according to the invention,emulsification is carried out by mixing the reaction product with 0.5 to20% by weight of water in the presence of 1 to 30% by weight surfactant,followed by at least one step of mixing the resulting emulsion withwater until the desired concentration of emulsified waxorganopolysiloxane blend in water is reached. The amount of waterpresent in the initial mixing step of the emulsification can for examplebe 1 to 10% based on the polymerization reaction product. In such aprocedure in which only a small amount of water is initially added tothe polymerization reaction product, a water-in-oil emulsion containinga continuous wax/silicone phase and a dispersed water phase can beformed, particularly if the amount of water is less than 5%. By applyingshear to the water-in-oil emulsion, a phase inversion of thewater-in-oil emulsion to a viscous oil-in-water emulsion is effected.The high shear mixing is preferably carried out in a mixer designed todeal with thick pastes such as a dental mixer. Further additions ofsmall amounts of water with high shear mixing may be carried out beforeoptionally diluting the oil-in-water emulsion by adding more water underlower shear.

The particle size of the emulsion can for example be within the range0.1 to 100 μm. The quantity of water and surfactant used in the initialphase inversion process may have an impact on the particle size of thefinal emulsion. For instance, if an emulsion is formed with the samequantity of water in two instances but in the first a large quantity ofwater is mixed before the phase inversion step and in the second a smallquantity of water is mixed before the phase inversion step followed bymixing the remaining additional water after the phase inversion step,the first emulsion will generally have a larger particle size than thesecond. No matter how the water is added, the total amount of water usedis generally between about 1 and 99 wt. %, preferably between about 6and about 99 wt. %, based on the weight of the emulsion.

Formulations containing the dispersion of polyorganosiloxane and wax cancontain various additives known in silicone formulations, for example“active materials” such as perfumes, sunscreens, vitamins, antioxidants,drugs, biocides, pest repellents, catalysts, natural extracts, peptides,warming effect and cooling agents, or fillers, colouring agents such asdyes, pigments and shimmers, heat stabilizers, flame retardants, UVstabilizers, fungicides, biocides, thickeners, preservatives, antifoams,freeze thaw stabilizers, or inorganic salts to buffer pH. Such materialscan be added to the mixture of organopolysiloxane and wax before, duringor after polymerisation. If added after polymerisation, they can beadded before or after the reaction product has been emulsified.

The “active material” is an organic material intended to have an effectin the formulation in which the polymerised organopolysiloxane is used.High molecular weight silicones are used in household care and personalcare applications often in conjunction with organic active materialingredients such as perfumes or essential oil. Often, significantamounts of the costly active material, for example perfume, are wastedduring the application not contributing to the end users benefit. Wehave found that by polymerizing the organopolysiloxane in the presenceof a wax according to the invention, we can incorporate perfume in theblend of wax and polymerized organopolysiloxane yielding shelf stableproducts which release the perfume only slowly, and may be controlled torelease the perfume or other active material in desired circumstances.Controlled release can be achieved particularly if the active materialis added before, during or after polymerisation, but before the reactionproduct has been emulsified.

One example of an active material is a fragrance composition (perfume).The fragrance composition may be solid or liquid and may be a singlefragrant compound, or a natural scented oil, or may be a mixture offragrant compounds and/or natural oils. Examples of such natural oilsand fragrant compounds are described in WO-A-01/25389; these naturaloils and fragrant compounds are in particular those suitable for use incleaning compositions for household or personal use, for example apowder or liquid laundry detergent, a fabric softener or an ironing aid,or for air fresheners. The fragrance composition may alternatively be aperfume for incorporation in a personal care product such as a skincream, shampoo or face cream, or a colour cosmetics product such as afoundation or mascara, or may be a flavour or aroma compound to beapplied for example to food or food packaging. The fragrance compositioncan alternatively comprise a chemically protected fragrance compoundsuch as a reaction product of the fragrance compound.

Perfumes generally dissolve easily in molten organic waxes. The perfumecan be mixed with the wax and then heated to melt the wax, or the waxcan be melted and then mixed with the perfume, or the molten wax can bemixed with the organopolysiloxane starting material and then mixed withthe perfume. Alternatively the perfume can be mixed with thepolysiloxane and wax during the polymerization reaction, that is afterthe catalyst has been added, or with the reaction product while the waxis still molten.

Alternative type of active material which can be incorporated in the waxsilicone composition include sunscreen materials, antioxidants,vitamins, insect repellents and warming effect and cooling agents(materials which give a warming or cooling sensation to the skin).Examples of sunscreens include those which absorb ultraviolet lightbetween about 290-320 nanometers (the UV-B region) such aspara-aminobenzoic acid derivatives and cinnamates such as octylmethoxycinnamate or 2-ethoxyethyl p-methoxycinnamate; and those whichabsorb ultraviolet light in the range of 320-400 nanometers (the UV-Aregion) such is benzophenones and butyl methoxy dibenzoylmethane.Examples of vitamins are vitamins A and E, retinol and tocopherol.Menthol is an example of a cooling agent. These materials can be used inpersonal care products. Sunscreens and vitamins are used in skin creamsand lotions and are released only slowly if they have been incorporatedin a wax silicone blend according to the invention. Cooling agentsincorporated in a wax silicone blend can be used in a skin carecomposition to give prolonged release of the cooling agent when thecomposition is rubbed into the skin. Insect repellent personal careproducts can for example be in the form of creams, sticks or sprays, andcontrolled release of the insect repellent from the personal careproduct is required after the product has been applied to the skin.

The invention can also be used to give controlled release of a drug (apharmaceutically active material) by incorporating the drug in a waxsilicone blend according to the invention and using this blend in acomposition which is applied to the skin to dose the drug by transdermaldelivery.

A further alternative type of active material which can be incorporatedin the wax silicone blend is a biocide, for example to give prolongedprotection against bacterial degradation of a composition including theblend or to give a prolonged biocidal effect to a substrate to which thecomposition has been applied.

A further alternative type of active material which can be incorporatedin the wax silicone blend is a catalyst. A wax silicone blend in which acuring catalyst has been incorporated can for example be used incoatings or adhesives where controlled release is advantageous to givethorough cure without curing too rapidly.

The wax can be chosen so that the active material is released inresponse to a change in temperature or in the environment encountered bythe wax silicone blend. For example the melting point of the wax can bechosen so that the perfume is released above the ironing temperaturewhen the wax silicone blend is used in products for ironing aid.Alternatively the wax can be sparingly soluble in water so that theperfume is slowly released when the wax silicone blend is used in aproduct applied in water, for example in fabric softener. Polyethyleneglycol polyether waxes for example are sparingly soluble in water.

The emulsions of the invention are useful in personal care applicationssuch as on hair, skin, mucous membrane or teeth. In these applications,the silicone is lubricious and will improve the properties of skincreams, skin care lotions, moisturisers, facial treatments such as acneor wrinkle removers, personal and facial cleansers such as shower gels,liquid soap, hand sanitizers and wipes, bath oils, perfumes, fragrances,colognes, sachets, deodorants, sun protection creams, lotions and wipes,colour cosmetics such as foundations and mascaras, self tanning creams,lotions and wipes, pre-shave and after shave lotions, after sun lotionand creams, antiperspirant sticks, soft solid and roll-ons, shavingsoaps and shaving lathers. It can likewise be use in hair shampoos,rinse-off and leave-on hair conditioners, hair styling aids, such assprays, mousses and gels, hair colorants, hair relaxers, permanents,depilatories, and cuticle coats, for example to provide styling andconditioning benefits. In cosmetics, the silicone functions as alevelling and spreading agent for pigment in make-ups, colour cosmetics,compact gel, cream and liquid foundations (water-in-oil and oil-in-wateremulsions, or anhydrous lotions), blushes, eye liners, eye shadows,mascaras, and make up removers. The emulsion of silicone and wax islikewise useful as a delivery system for oil and water solublesubstances such as vitamins, fragrances, emollients, colorants, organicsunscreens, or pharmaceuticals. When the emulsion is used in personalcare products, the polyorganosiloxane generally comprises about 0.01 toabout 50 weight percent, preferably 0.1 to 25 wt. percent, of thepersonal care product.

The emulsions produced according to the invention are also useful inother applications such as paints, water based coatings, textile fibretreatment, leather lubrication, fabric softening, fabric care in laundryapplications, homecare, release agents, and oil drag reduction, and inother areas where silicone emulsions are conventionally used. Thewax/silicone dispersions have particular advantages in oil dragreduction resulting from increased compatibility with hydrocarbonfluids, especially when the wax is a hydrocarbon wax.

The invention is illustrated by the following Examples, in which partsand percentages are by weight. Catalyst levels given in ppm and arebased on the polysiloxane content.

The molecular weight of the siloxanes in the blends was determined bygel permeation chromatography (GPC). The analyses have been performed byGPC (Alliance Waters 2690) using triple detection (Refractive indexdetector, Viscometer and Light Scattering Detectors) and toluene assolvent. Molecular weight averages were determined by universalcalibration relative to a triple detection calibration realized on asingle point using polystyrene narrow standard (Mw 70,950 g/mol).

The consistency of cooled blends was tested with a needle penetrometeraccording to ASTM D217-97 at 25° C. and results are reported in mm/10*3sec.

Example 1

20 parts Dow Corning HY-3050 soy wax having a melting point of about 55°C. was and mixed and melted at 80° C. with 80 parts of a dimethylhydroxyl terminated polydimethylsiloxane (having a viscosity of 70 mPa·sat 25° C. measured with a Brookfield LV DV-E viscometer, a Mn of 2500g/mol and a Mw of 3500 g/mol) to form a liquid/liquid dispersion. 30parts per million (ppm) of the ionic phosphazene[Cl(PCl₂═N)_(x)PCl₃]⁺[PCl₆]⁻ diluted in dichloromethane was added ascatalyst. The polymerisation was carried out in a 1 l glass reactor at80° C. under vacuum. The polymerisation was stopped, by the addition of0.012 parts of trihexylamine, after 14 minutes. The polymerisedpolydimethylsiloxane has Mn 96 kg/mol and Mw 131 kg/mol.

An emulsion was prepared by adding 0.8 g Volpo L4 and 1.2 g Volpo L23polyoxyethylene lauryl ether non-ionic surfactants and 1 g water to 20 gof the above dispersion at 80° C. and mixing for 20 seconds at 3000 rpmin a Hausschild dental mixer. An additional 1.0 g of water was added andmixing repeated under the same conditions. Addition of 1.0 g water andmixing was repeated 4 more times. Further additions of water andsubsequent mixing were carried out until 18 g water had been added intotal, yielding a milky white emulsion with 50% active content. The soobtained emulsion has a particle size of D(v, 0.5) μm=0.61 and D(v, 0.9)μm=1.13 (determined using a Malvern Mastersizer 2000)

Example 2

20 parts of Dow Corning HY-3050 soy wax was mixed and melted at 60° C.with 60 parts of the dimethyl hydroxyl terminated polydimethylsiloxaneof Example 1 and 20 parts ‘Gemseal 25’ (supplied by Total) cosmeticgrade mineral oil to form a liquid/liquid dispersion. 30 ppm[Cl(PCl₂═N)_(x)PCl₃]⁺[PCl₆]⁻ diluted in dichloromethane was added ascatalyst. The polymerisation was carried out in a 1 l glass reactor at60° C. under vacuum. The polymerisation was stopped, by the addition of0.009 parts of trihexylamine, after 31 minutes. The polymerisedpolydimethylsiloxane has Mn 73 kg/mol and Mw 103 kg/mol.

An emulsion was prepared by adding 2 g Lutensol T08 ethoxylated oxoalcohol non-ionic surfactant sold by BASF and 1 g water to 25 g of theabove dispersion at 60° C. and mixing for 20 seconds at 3000 rpm in aHausschild dental mixer. An additional 1.0 g of water was added andmixing repeated under the same conditions. Addition of 1.0 g water andmixing was repeated 3 more times yielding a cream with 80% (siliconeplus organics) active content. The cream obtained has a particle size ofD(v, 0.5) μm=0.28 and D(v, 0.9) μm=0.50 (determined using a MalvernMastersizer 2000).

Example 3

20 parts of a Candelilla wax having a melting range of about 68.5-72.5°C. (supplied under the name SP75 from Strahl & Pitsch) was melted at 75°C. and mixed at 75° C. with 80 parts of the dimethyl hydroxyl terminatedpolydimethylsiloxane of Example 1 to form a liquid/liquid dispersion. 20ppm [Cl(PCl₂=N)_(x)PCl₃]⁺[PCl₆]⁻ diluted in dichloromethane was added ascatalyst. The polymerisation was carried out in a 1 l glass reactor at75° C. under vacuum. The polymerisation was stopped after 29 minutes, bythe addition of 0.013 parts of trihexylamine, A liquid/liquid dispersioni.e. an emulsion of the wax and high molecular weightpolydimethylsiloxane was produced and was cooled to room temperature Thepolymerised polydimethylsiloxane has Mn 221 kg/mol and Mw 285 kg/mol.The dispersion had a penetration of 19 mm/10*3 sec.

Example 4

The polymerisation reaction of Example 1 was repeated using 10 parts DowCorning HY-3050 soy wax and 90 parts dimethyl hydroxyl terminatedpolydimethylsiloxane at 70° C. using 10 ppm catalyst. The reaction wasstopped after 2 minutes by the addition of 0.008 parts of trihexylamine.The polymerised polydimethylsiloxane has Mn 467 kg/mol and Mw 567kg/mol. The dispersion was stored at 70° C. during 4 hours and cooleddown to room temperature without showing any signs of macroscopic phaseseparation. The dispersion had a penetration of 40 mm/10*3 sec.

Example 5

20 parts of a shea butter having a melting range of about 28-38° C.(supplied under the name HY-3003 from Dow Corning) was mixed and meltedat 70° C. with 80 parts of the dimethyl hydroxyl terminatedpolydimethylsiloxane of Example 1 to form a liquid/liquid dispersion. 10ppm [Cl(PCl₂=N)_(x)PCl₃]⁺[PCl₆]⁻ diluted in dichloromethane was added ascatalyst. The polymerisation was carried out in a 1 l glass reactor at70° C. under vacuum. The polymerisation was stopped after 2 minutes, bythe addition of 0.007 parts of trihexylamine, A liquid/liquid dispersionof the butter and high molecular weight polydimethylsiloxane wasproduced and was cooled to room temperature forming a paste. Thepolymerised polydimethylsiloxane produced has Mn 383 kg/mol and Mw 464kg/mol. The dispersion had a penetration of 56 mm/10*3 sec.

Facial creams of the water in oil emulsion type were prepared using theblends prepared in Examples 3 to 5. The formulations are given in thefollowing table.

a b c Ingredients INCI (%) (%) (%) Phase A Dow Corning ® 5200 LaurylPEG/PPG- 2.00 2.00 2.00 Formulation Aid 18/18 Methicone Dow Corning ®FZ-3196 Caprylyl Methicone 12.00 12.00 12.00 Cetiol CC DicaprylylCarbonate 12.00 12.00 12.00 polysiloxane-in-Candelilla Example 3 4.00 —— Wax polysiloxane-in-Soy Wax Example 4 — 4.00 — polysiloxane-in-SheaButter Example 5 — — 4.00 Phase B Water Water 64.00 64.00 64.00 GlycerinGlycerin 5.00 5.00 5.00 Sodium Chloride Sodium Chloride 1.00 1.00 1.00PEG = polyethylene glycol, PPG = polypropylene glycolThe following procedure was used:1. Mix phase A ingredients together and heat to 85° C. under water bathuntil melted2. Mix phase B ingredients together and heat to 85° C.3. Slowly add phase B to phase A at 1000 rpm4. When all phase B is added, mix for an additional 5 minutes at1800-2000 rpm5. Let cool down to room temperature mixing slowly

All the facial cream formulations were homogenous and stable for atleast 1 month at room temperature and at 40° C.

The invention claimed is:
 1. A method of producing an aqueous emulsion of a polyorganosiloxane and a wax, wherein an organopolysiloxane is polymerized in an admixture with a molten wax, thereby forming a blend of the wax with an organopolysiloxane of increased molecular weight, and the blend of polymer and molten wax is emulsified in water in the presence of a surfactant, wherein the organopolysiloxane is a substantially linear organopolysiloxane containing at least one hydroxyl or hydrolysable group bonded to silicon and is polymerized by catalysed condensation of the hydroxyl or hydrolysable group(s) to form siloxane bonds or wherein the organopolysiloxane comprises a cyclic organopolysiloxane and is polymerized by a catalysed process of ring opening of the cyclic organopolysiloxane to form siloxane bonds.
 2. The method according to claim 1, wherein the organopolysiloxane is a mixture of a substantially linear organopolysiloxane containing at least one hydroxyl or hydrolysable group bonded to silicon and an alkoxysilane having an average of more than two alkoxy groups per molecule, and is polymerized by catalysed siloxane condensation of the substantially linear organopolysiloxane with the alkoxysilane to form a branched organopolysiloxane structure.
 3. The method according to claim 1, wherein the substantially linear organopolysiloxane is a polydimethylsiloxane having terminal hydroxyl groups bonded to silicon and having a viscosity between 10 mPa·s and 500 mPa·s.
 4. The method according to claim 1, wherein the polymerization is catalysed by a phosphazene catalyst, a Lewis acid or base.
 5. The method according to claim 1, wherein the wax has a melting point in the range 30 to 80° C.
 6. The method according to claim 1, wherein the wax is a hydrocarbon wax, an ester wax or a silicone wax.
 7. The method according to claim 1, wherein the weight ratio of organopolysiloxane to wax present during the polymerization is from 95:5 to 40:60.
 8. The method according to claim 1, wherein the surfactant is a nonionic surfactant.
 9. The method according to claim 1, wherein the blend of the wax with an organopolysiloxane of increased molecular weight produced in the polymerization reaction is emulsified before the reaction product has cooled to a paste or solid.
 10. The method according to claim 1, wherein the blend of the wax with an organopolysiloxane of increased molecular weight produced in the polymerization reaction is cooled to a paste or solid and is subsequently heated to melt the wax and emulsified at a temperature above the melting point of the wax.
 11. The method according to claim 1, wherein the emulsification is carried out by mixing the blend of polymer and wax with 1 to 20% by weight of water in the presence of 1 to 30% by weight surfactant, followed by at least one step of mixing the resulting emulsion with water until the desired concentration of emulsified wax organopolysiloxane blend in water is reached.
 12. A method of producing an aqueous emulsion of a polyorganosiloxane and a wax, wherein an organopolysiloxane is polymerized in an admixture with a molten wax, thereby forming a blend of the wax with an organopolysiloxane of increased molecular weight, and the blend of polymer and molten wax is emulsified in water in the presence of a surfactant, wherein the organopolysiloxane is polymerized via a hydrosilylation reaction between an organopolysiloxane containing alkenyl groups or alkynyl groups and an organopolysiloxane having Si—H groups in the presence of a platinum group catalyst. 